Compatibility - This silicone bellow hopper is designed for Barista Express, Barista Touch, Barista Pro, Smart Grinder Pro, Smart Grinder, Dose Control Pro, Dose Control. The lid creates a nice seal on the top, no air leakage anywhere when press down. Zero retention - Frequent use of a grinder allows for residual coffee to accumulate on the burrs. This silicone bellow allow for the air space when placed on between the lid and the top of the bean reserve to be used to blow out the particles after a grind so that coffee is not left behind to clog the blades, so that the coffee flavour will not be affected by remainder accumulation of previous . Food-grade & Anti-dust silicone material - This silicone bellow hopper is made of food-grade material and anti-dust surface process. Easy to Use - Please put the silicone bellow on dosing hopper and then the lid just sits on top of it. It is suggested to cycle 2-3 times grinding & pumping operation. Colour:grey Material:Silica gel Size:155 x 50mm Package Contents: 1 x silicone bellow Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.